U.S. patent application number 14/079244 was filed with the patent office on 2014-03-06 for method and device for lubricating rollers and a rolled strip of a rolling stand.
This patent application is currently assigned to SMS Siemag Aktiengesellschaft. The applicant listed for this patent is SMS Siemag Aktiengesellschaft. Invention is credited to Hartmut PAWELSKI, Hans-Peter RICHTER, Jurgen SEIDEL.
Application Number | 20140060135 14/079244 |
Document ID | / |
Family ID | 41335046 |
Filed Date | 2014-03-06 |
United States Patent
Application |
20140060135 |
Kind Code |
A1 |
PAWELSKI; Hartmut ; et
al. |
March 6, 2014 |
METHOD AND DEVICE FOR LUBRICATING ROLLERS AND A ROLLED STRIP OF A
ROLLING STAND
Abstract
A method for lubricating rolls, especially work rolls of a
rolling stand, and rolling stock passed between the rolls during
the rolling operation, in which a lubricant-gas mixture, a
lubricant-water-gas mixture, a lubricant-water mixture and/or a
grease-medium mixture is applied to the rolls or the rolling stock
on the run-in side of the rolling stand, wherein the mixture is
prepared with at least one mixing device in the area upstream of
the rolling stand.
Inventors: |
PAWELSKI; Hartmut;
(Ratingen, DE) ; RICHTER; Hans-Peter; (Friedewald,
DE) ; SEIDEL; Jurgen; (Kreuztal, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SMS Siemag Aktiengesellschaft |
Dusseldorf |
|
DE |
|
|
Assignee: |
SMS Siemag
Aktiengesellschaft
Dusseldorf
DE
|
Family ID: |
41335046 |
Appl. No.: |
14/079244 |
Filed: |
November 13, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
13000281 |
Jan 25, 2011 |
|
|
|
PCT/EP2009/004138 |
Jun 9, 2009 |
|
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14079244 |
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Current U.S.
Class: |
72/41 |
Current CPC
Class: |
B21B 45/0263 20130101;
B21B 37/32 20130101; B21B 45/0251 20130101; B21B 45/0248 20130101;
B21B 27/10 20130101; B21B 38/02 20130101; B21B 45/0245
20130101 |
Class at
Publication: |
72/41 |
International
Class: |
B21B 45/02 20060101
B21B045/02 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 18, 2008 |
DE |
10 2008 028 620.6 |
Jul 21, 2008 |
DE |
10 2008 034 099.5 |
Oct 2, 2008 |
DE |
10 2008 050 392.4 |
Claims
1. A device for lubricating at least one roll and/or rolling stock
rolled between rolls in a rolling stand, comprising: at least one
mixing block and/or multicomponent mixing devices for mixing water,
gas, and at least one lubricant to form a lubricant-gas mixture, a
lubricant-water-gas mixture, or a lubricant-water mixture; and
automatic control devices for determining an amount of the mixture
to be sprayed by spray devices onto at least one of the rolls
and/or onto the rolling stock.
2. The device in accordance with claim 1, wherein the automatic
control devices are arranged in zones over a width of the at least
one roll or the rolling stock.
3. The device in accordance with claim 1, and further comprising
flowmeters and pressure controllers.
4. The device in accordance with claim 1, wherein the
multicomponent mixing devices are internal mixers or external
mixers, wherein the multicomponent mixing devices comprise one of
the group consisting of a turbulence plate, a venturi tube and a
pipe construction.
5. The device in accordance with claim 1, and further comprising
water spray bars provided above and/or below the spray devices for
spraying the lubricant-containing mixture onto at least one roll
and/or onto the rolling stock.
6. The device in accordance with claim 1, and further comprising
walls arranged to laterally shield a lubricant-air mist produced by
the spray devices, and further comprising an exhaust system for the
mist, wherein the walls are inwardly swivelable toward the rolls or
the rolling stock.
7. The device in accordance with claim 1, and further comprising an
automatic control device for controlling flatness of the rolled
strip by evaluating signals of a flatness measuring device, wherein
the flatness measuring device comprises a measuring roller or
contactless measuring device, which generates signals that
correspond to the flatness of the rolled strip, the flatness
measuring device being operative to relay the signals to the spray
devices for adjusting amounts or concentrations of the at least one
lubricant.
8. The device in accordance with claim 1, wherein the spray devices
are arranged in two rows substantially parallel to an axis of the
work roll.
9. The device in accordance with claim 8, wherein the rows are
offset from each other.
10. The device in accordance with claim 1, wherein the spray
devices are arranged in a single row, and have nozzles with a large
angle of spray so that adjacent jets provide double coverage.
11. The device in accordance with claim 1, wherein the mixing
devices are atomizing nozzles.
12. The device in accordance with claim 1, wherein the lubricant is
oil.
13. The device in accordance with claim 1, wherein the automatic
control devices are control valves.
14. A rolling stand, comprising a device according to claim 1,
wherein the spray devices have nozzle spray bars designed to
swivel, so that a distance between a nozzle orifice and the roll or
rolling stock can be adjusted to be minimal or optimal.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a Divisional Application of U.S.
patent application Ser. No. 13/000,281, filed Jan. 25, 2011, which
is a 371 of International application PCT/EP2009/004138, filed Jun.
9, 2009, which claims priority of DE 10 2008 028 620.6, filed Jun.
18, 2008, and DE 10 2008 034 099.5, filed Jul. 21, 2008, and DE 10
2008 050 392.4, filed Oct. 28, 2008, the priority of these
applications is hereby claimed and these applications are
incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] The invention concerns a method for lubricating rolls,
especially work rolls of a rolling stand, and rolling stock passed
between the rolls during the rolling operation, in which a
lubricant-gas mixture, a lubricant-water-gas mixture, a
lubricant-water mixture, and/or a grease-medium mixture is applied
to the rolls or the rolling stock on the run-in side of the rolling
stand.
[0003] The rolling stand comprises several mutually supporting
rolls, including, for example, a work roll, which comes into direct
contact with the rolling stock and in turn rolls on a generally
larger backup roll or intermediate roll. Many hot rolling mills for
rolling a metal strip have an integrated roll gap lubricating
system. These systems are used for the purpose of improving the
surface quality of the work roll and the strip and have become part
of the standard equipment of a rolling mill on which high-quality
strip is to be produced. In one widely used system, a mixture of
water as the base medium with oil is applied to the rolling stock
or to the work roll or backup roll.
[0004] In the cold rolling process, lubrication is customary. In
this case, lubricant is applied to the rolling stock and/or to the
work roll and/or is sprayed into the roll gap. The mixing of the
oil and water is carried out far from the rolling stand. In most
cases, an emulsion is used, which, in a complicated process in a
circulation system, is separated, cleaned and resupplied to the
lubricating system.
[0005] WO 03 002277 A1 discloses a method and a device for cooling
and/or lubricating rolls, especially work rolls, of a rolling
stand, in which water in the form of spray jets is used as a
cooling medium, and oil, an oil-air mixture, an oil-water mixture,
an oil-water-air mixture, or grease mixtures are used as
lubricants. To improve the lubricating and cooling effect, the
combined use of supercooling of the strip and roll surface and roll
lubrication on the run-in side of the rolling stand is proposed, in
which the two media--water and lubricant--are supplied separately
to the rolls and the rolling stock and are applied to different
points of application on the surface of the roll. Separate supply
lines to the spray bars are provided for water and the
lubricant.
SUMMARY OF THE INVENTION
[0006] The objective of the invention is to create a simplified
method of lubrication during the rolling of a metal strip, which
can be used both in cold rolling and in hot rolling.
[0007] In accordance with the invention, this objective is achieved
in a method of the aforementioned type by preparing the mixture
with at least one mixing device in the area upstream of the rolling
stand. In the cold rolling process, much as in the hot rolling
process, the goal of the new lubricating method is to produce the
lubricant just before its use or application and thus to avoid the
complicated preparation in a closed circulation. To realize
economical use of the method, a further goal of the invention is to
minimize the amount of lubricant that is used. The same goal also
applies to the use of the lubricating method of the invention for
hot rolling. While reducing the amount of lubricant that is used,
at the same time it is intended that the lubricating action be
optimized and that it be possible to adjust the lubricating
effect.
[0008] Examples of lubricants that can be used are oil-water
dispersions, oil-water emulsions, oil-free water-miscible
lubricants, oil-air mixtures, or oil-water-air mixtures. The media
can be sprayed in 2-, 3- or 4-component nozzles.
[0009] To reduce the amount of lubricant, it is especially
advantageous to atomize the lubricant with air. In a preferred
embodiment, oil and water are mixed just before being atomized with
air. This makes it possible to apply even extremely small amounts
of oil to the surfaces of the rolls or to the rolling stock. In the
case of hot rolling, the mixing of oil and water has the advantage,
compared to the use of pure oil, that there is no fire hazard.
[0010] In the case of cold rolling, the new method of lubrication
has the advantage that the oil concentration in the lubricant can
be varied very quickly and flexibly. In this way, the lubricant can
be optimally adjusted to different materials to be rolled, to
different strip speeds, to varying drafts, and to the given rolling
stand. In addition, it is also possible to prepare different oils
and lubricants for different applications.
[0011] Since the amounts of lubricant are so small that just the
roll and/or strip surface is wetted, there is no need for a
complicated preparation process. The used lubricant, together with
the water from the cooling systems and possibly other oil leakages,
is conveyed to the wastewater treatment plant, and the oil is
separated there.
[0012] Advantageous refinements of the invention are described in
the dependent claims.
[0013] One of the advantageous provisions of the invention is that
water and at least one lubricant are conveyed to a mixer through
separate supply lines and are mixed in the mixer to form a
water-lubricant dispersion or emulsion. In this connection, it can
be provided that the water-lubricant dispersion or emulsion is
atomized in atomizing nozzles by means of a gas, especially air,
and applied to at least one of the work rolls and/or to the rolling
stock.
[0014] 3-component or 4-component mixing nozzles or atomizing
nozzles, in which the water, the one or more lubricants, and the
air are mixed, are preferably used. Naturally, it is possible, in
accordance with the invention, to use a gas other than air or to
use a mixture of gases.
[0015] Preferably, the one or more lubricants are first mixed with
the water in a supply line to form a mixture, and then the mixture
is mixed with the gas in the inner chamber of the 3-component or
4-component mixing nozzle. Alternatively, the water, the one or
more lubricants, and the gas are mixed in the inner chamber of the
3-component or 4-component mixing nozzle.
[0016] The lubricant-gas mixture, the lubricant-water-gas mixture,
the lubricant-water mixture and/or the grease-medium mixture is
preferably distributed over the entire width of at least one of the
work rolls and/or the rolling stock.
[0017] It has also been found to be advantageous if the amount of
water, the one or more lubricants, the gas, the lubricant-gas
mixture, the lubricant-water-gas mixture, the lubricant-water
mixture and/or the fat-medium mixture is distributed by means of
control valves over the width of at least one of the work rolls
and/or the rolling stock.
[0018] In another embodiment of the method, it is provided that the
amount and/or the pressure of the one or more lubricants, the
water, the lubricant-water mixture, the lubricant-gas mixture,
and/or the fat-medium mixture is automatically controlled over the
width of at least one of the work rolls and/or the rolling stock by
means of the control valves and/or in flowmeters, pressure
controllers, and/or in mixing blocks.
[0019] It can also be provided that the one or more lubricants,
water and gas are mixed in a 3-component nozzle, wherein the amount
of lubricant is automatically controlled in sectors over the width
of at least one of the work rolls and/or the rolling stock, and
that the pressure and/or the volume of the gas and the water is
automatically controlled.
[0020] Alternatively, the mixing operation is realized in such a
way that the one or more lubricants and the gas are mixed in a
mixing block and that water is then added in 2-component mixing
nozzles. In this case, the water can be admixed outside an inner
nozzle tube of the 2-component mixing nozzles.
[0021] In another advantageous embodiment of the method, the one or
more lubricants are mixed with the gas, especially in a mixing
block, and sprayed by nozzles onto at least one of the rolls and/or
the rolling stock, while water is sprayed next to the nozzles.
[0022] Preferably, a flatness control system is used to
automatically control the supply of the one or more lubricants in
zones over the width.
[0023] The invention also concerns a device for lubricating at
least one roll and/or rolling stock rolled between the rolls in a
rolling stand.
[0024] In accordance with the invention, the device is
characterized by the fact that it has at least one mixing block
and/or multicomponent mixing devices, especially atomizing nozzles,
for mixing water, gas, and at least one lubricant, especially an
oil, to form a lubricant-gas mixture, a lubricant-water-gas
mixture, or a lubricant-water mixture.
[0025] It is advantageous for the device to have automatic control
devices, especially control valves, for determining the amount of
the mixture to be sprayed by spray devices onto at least one of the
rolls and/or onto the rolling stock.
[0026] It is advantageous for the automatic control devices to be
arranged in zones over the width of the one or more rolls or the
rolling stock. In this connection, it is also possible to provide
flowmeters and pressure controllers.
[0027] The multicomponent mixing devices are designed either as
internal mixers or external mixers. Preferably, they comprise a
turbulence plate or a venturi tube.
[0028] It is advantageous to provide water spray bars above and/or
below spray devices for spraying a lubricant-containing mixture
onto at least one roll and/or onto the rolling stock. This has a
fire protection effect in the case of hot rolling. Flammable oil or
lubricant is shielded by a water spray curtain and thus cannot heat
up and cause a fire.
[0029] In addition, it is advantageous to equip the device with an
automatic control device for controlling the flatness of the rolled
strip by evaluating signals of a flatness measuring device,
especially a flatness measuring roller.
[0030] The flatness measuring device preferably comprises a
flatness measuring roller, which generates signals that correspond
to the flatness of the rolled strip and relays the signals to the
spray devices for the purpose of adjusting the amounts or
concentrations of the one or more lubricants. The use of the
flatness measuring device makes it possible to consider even higher
order flatness of the rolled strip by evaluation of the signals of
the flatness measuring roller, and corrective measures can be
taken, for example, by changing the amounts or concentrations of
the lubricant.
[0031] The spray devices are preferably arranged in two rows
essentially parallel to the axis of the roll, especially offset
from each other, so that even in the event of failure of some of
the spray nozzles, adequate lubrication of the roll surface or of
the rolling stock can still be guaranteed.
[0032] The invention also concerns a rolling stand, in which a
device of the type described above is used for lubricating a roll
and/or the rolling stock.
[0033] The various features of novelty which characterize the
invention are pointed out with particularity in the claims annexed
to and forming a part of the disclosure. For a better understanding
of the invention, its operating advantages, specific objects
attained by its use, reference should be had to the drawings and
descriptive matter in which there are illustrated and described
preferred embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWING
[0034] In the drawings:
[0035] FIG. 1 shows a rolling installation with an oil-water-air
lubricating system, which has a lubricant supply that is variable
over the width and in which the lubricant is sprayed onto the upper
work roll.
[0036] FIG. 2 shows a rolling installation with an oil-water-air
lubricating system, in which the lubricant is sprayed onto the
upper work roll in equal amounts over the length.
[0037] FIG. 3 shows a rolling installation with an oil-water-air
lubricating system, which has a lubricant supply that is variable
over the width and in which the lubricant is sprayed onto the
underside of the rolling stock.
[0038] FIG. 4 shows a rolling installation with an oil-water-air
lubricating system, which has a plurality of 3-component mixing
nozzles with gas-liquid atomizers and in which the lubricant is
sprayed onto the upper work roll.
[0039] FIG. 5 shows an embodiment of a 3- or 4-component mixing
nozzle for mixing water, lubricant and gas, as used, for example,
in the rolling installation illustrated in FIG. 3.
[0040] FIG. 6 shows a two-row arrangement of mixing nozzles for
applying lubricant to a roll or rolling stock.
[0041] FIG. 7 shows a rolling installation with an oil-water-air
lubricating system with a plurality of 3-component mixing nozzles
with gas-liquid atomizers and with control valves assigned to each
3-component mixing nozzle for automatically controlling the amount
of lubricant, in which the lubricant is sprayed onto the upper work
roll.
[0042] FIG. 8 shows a rolling installation with an oil-water-air
lubricating system, in which lubricant and gas are mixed in a
mixing block, and water is added in a plurality of 2-component
mixing nozzles, and the lubricant is sprayed onto the upper work
roll.
[0043] FIG. 9 shows the mixing block according to FIG. 8 in
combination with a 2-component mixing nozzle in longitudinal
section, wherein the media mix outside the mixing nozzle.
[0044] FIG. 10 shows a 3-component mixing nozzle for mixing water,
lubricant and gas with a mixture of the liquid media before
entrance into the medium chamber in longitudinal section.
[0045] FIG. 11 shows another 3-component nozzle for mixing water,
lubricant and gas with a mixture of the liquid media before
entrance into the medium chamber in longitudinal section, wherein
all of the media mix in the medium chamber.
[0046] FIG. 12 shows a rolling installation with an oil-water-air
lubricating system, in which lubricant and gas are mixed in a
mixing block, the lubricant is sprayed onto both work rolls, and at
the same time water spray bars are provided as fire protection
devices.
[0047] FIG. 13 shows the rolling installation according to FIG. 7
but with the addition of a flatness measuring roller and a flatness
control system.
DETAILED DESCRIPTION OF THE INVENTION
[0048] A rolling installation 1 (FIG. 1) comprises two work rolls
2, 3, which are supported between two backup rolls 4, 5 and roll
rolling stock 6 (FIG. 3). In this operation, a lubricant,
especially a first and a second oil, or additional oils and water
are first supplied via separate supply lines 7, 8, and 9. First,
the two oils are mixed together. Alternatively, only one oil or the
other is used. The desired amounts of water and the two oils are
adjusted by metering pumps 10, 11 and pumped to a mixer 12. A
dispersion or emulsion of the two liquids brought together in this
way is formed downstream of the mixer 12. To avoid separation of
the mixture, the distance between the mixer 12 and control valves
13 downstream of the mixer is preferably very small, or the mixer
and control valves are constructed as a single unit. The control
valves 13 are distributed over the entire width of the upper work
roll 2. If relatively long pipelines cannot be avoided, turbulence
plates (mixers) are installed a certain distance apart in the
lines. The pipeline cross section is preferably selected as small
as possible in order to realize a flow rate as high as possible and
thus a short conveyance time. To be able to adjust a lubricant load
over the width of the work roll 2 and also to be able to adjust it
as a function of the width of the rolling stock 6 that is being
processed, the control valves 13 deliver lubricant to downstream
atomizing nozzles 14, which are designed as 2-component mixing
nozzles, according to the width of the rolling stock 6. In the
atomizing nozzles 14, air is added to the mixture of lubricant and
water. The air is supplied through a line 15 with a pressure
controller for adjusting the air pressure. The amounts of lubricant
or oil and the amounts of water are adjusted by a computer model
and/or an automatic control device, which takes into account the
various lubricating properties as a function of the strip material
to be rolled, the strip speed, the draft, the temperatures and
other parameters. The activation of the control valves 13 and the
amounts pumped by the metering pumps 10, 11 are coordinated with
each other. The automatic control device determines the lubricant
concentrations or the types of lubricants and also carries out
automatic crown and flatness control of the rolled strip 6.
Unflatness of the rolled strip 6 is then compensated by adjusting
the amounts of lubricant supplied or by varying other parameters.
If necessary, the level of rolling force can be controlled by
varying the amount of oil, the type of oil, the concentration of
oil in the water and/or the oil mixing proportions.
[0049] In a simplified embodiment of the rolling installation 1
(FIG. 2), there are no control valves 13. In this case, the flow
through the atomizing nozzles 14 is manually adjusted or results
from the adjustment of the metering pump. In another embodiment
(FIG. 3), the lubricant-water-air mixture is applied directly to
the underside of the rolling stock 6. Control valves 13 are also
provided in this case.
[0050] In another embodiment (FIG. 4), water, the lubricant, for
example, oil, and air are first supplied through separate lines 7,
9, 15 and then applied to the upper work roll 2 by atomizing
nozzles 14 or 17 in the form of 3-component nozzles, wherein the
mixing and atomizing of the fluids constitute a unit in the
atomizing nozzles 17. However, in this case as well, control
devices can be provided, which individually control the supply of
the given fluid to the individual atomizing nozzles 17 or to a
group of atomizing nozzles. Preferably, all of the individual
automatic control devices are integrated in an automatic control
system, which determines the volume and the mixing proportions of
the fluids that are delivered by the atomizing nozzles 17 to the
work roll 2 or the rolling stock 6. Naturally, in all of the
embodiments (FIGS. 1 to 4), analogous designs are provided or can
be provided for supplying a lubricant-water-air mixture to the
lower work roll 3 and/or to the upper side of the rolling stock
6.
[0051] An atomizing nozzle 17 (FIG. 5) is realized as an internal
mixer pressure mixing nozzle with an inner chamber 18, into which
water and two lubricants are fed at one end through a supply line
19 and, if necessary, are mixed by means of, e.g., turbulence
plates 36 or a pipe constriction 37. The operation of mixing the
liquids takes place just before the atomization. The mixer and
nozzle constitute a unit here. Two lines 20, 21 first carry the
lubricants into the supply line 19 immediately before the
lubricants are delivered into the inner chamber 18. A gas,
especially air, enters the inner chamber 18 through another feed
line 22 and is mixed in the inner chamber 18 with the mixture of
water and the two lubricants. The mixture then leaves the nozzle
orifice 23 in a conical spray and strikes the surface of a roll or
the surface of the rolling stock 6. Since the lubricant (for
example, oil) or a plurality of lubricants is the most important
component, it is also possible, in accordance with the invention,
to control only the individual amount of oil per atomizing nozzle
17 and to control the other components in sections, i.e., over
relatively large sections of the width of a roll and/or the width
of the rolling stock 6. The lubricant or lubricants can also be
applied solely with the use of compressed air, i.e., without the
use of water. In this case, a 2-component nozzle is used.
[0052] Especially in the case of cold rolling, it is important that
the lubricant film acts completely over the entire width of the
rolling stock 6. If the oil film breaks down, undesirable scratches
are produced on the surface. To guarantee redundancy of the
lubricant effect, two or more rows 24, 25 (FIG. 6) of atomizing
nozzles 17 are preferably provided opposite a roll, for example,
work roll 2, or opposite the rolling stock 6. The atomizing nozzles
17 in the two or more rows 24, 25 are preferably offset from one
another. Alternatively, a one-row nozzle spray bar can be used,
whose nozzles have a large angle of spray, so that double coverage
is realized. This means that if one nozzle fails, the adjacent
nozzles cover this area.
[0053] Similarly to the embodiments illustrated in FIGS. 1 and 3,
other embodiments of the invention have automatic control devices
26 (FIG. 7), with which the supply of the lubricant to each
atomizing nozzle 14 is individually controlled over the entire
width of the strip. The overall effect of the lubrication can be
further influenced by varying the amounts of water and air. In the
case of hot rolling, lubricant is applied to at least one of the
work rolls 2, 3, while in the case of cold rolling, lubricant is
preferably applied to the rolling stock 6.
[0054] According to another variant (FIG. 8), lubricant and air are
brought together in a mixing block 27. The air carries the
lubricant to the atomizing nozzles 14. Each of the nozzles 14 is
individually fed. The water is supplied to the nozzles 14
separately.
[0055] In the mixing block 27 (FIG. 9), first the lubricant and air
from the lines 7 and 15 are brought together. The mixture is then
fed by a line 28 to a 2-component nozzle 29, in which it is
combined with water supplied by the line 8. The 2-component nozzle
29 is designed as an external mixer. This means that the
lubricant-air mixture and the water do not come together until they
reach the nozzle orifice 30. The mixing is made possible by two
hollow cones formed by the fluids spraying into each other. The
advantage of this 2-component nozzle 29 is that saponification is
prevented, since the lubricant and water do not come into contact
with each other until they arrive at the nozzle orifice 30. The
water supply can be shut off to realize pure lubricant-air
lubrication.
[0056] In a 2-component nozzle 31 (FIG. 10), which is designed as
an internal mixer with an inner chamber 32, oil and water are first
introduced together into the inner chamber 32 through a feed line
33, and air is introduced separately. Turbulence plates 34 or a
venturi tube is installed in the oil-water supply line 33 to
guarantee thorough mixing of the media.
[0057] A 3-component nozzle (FIG. 11) likewise has an inner chamber
32, into which the media oil, water and air are separately fed
through lines 7, 8, and 15. The liquid media are thus not mixed
until they reach the inner chamber 32, and they are then atomized
and sprayed.
[0058] When one wishes to use an oil-air mixture without having to
add water as an additional component, then in the case of hot
rolling, provision is made for fire protection, when necessary, by
producing a water curtain that shields the oil-air mixture towards
the outside by means of water spray bars 38, 39 (FIG. 12). In
addition, shielding walls 40, 41 are placed around the oil-air mist
produced by the atomizing nozzles 14. The oil-air mist can be
exhausted to the outside. The shielding walls 40, 41 as well as the
nozzle spray bars 14 are designed to swivel in order to improve the
shielding and to allow the nozzles to be placed just in front of
the roll. Similar exhausting is also provided for the lubricant
application to the rolling stock (in the case of cold rolling).
[0059] In another embodiment of the invention, to control the
surface structure (flatness, uniform state of stress) of the rolled
strip 6, a flatness measuring roller 42 (FIG. 13) or other type of
contactless (optical) flatness measuring system is provided to
determine unevenness of the rolled strip 6. This measuring system
transmits signals via a signal line 43 to an evaluation unit (not
shown here). The evaluation unit generates signals for controlling
or regulating the atomizing nozzles 14 or control valves 13 to
deliver properly adjusted amounts of lubricant to the work roll 2
over the width of the strip. Parabolic or higher order strip
flatness can be influenced by the amount or concentration of
lubricant delivered per zone. Naturally, corresponding automatic
control can also be applied with respect to the lower work roll 3.
The atomizing nozzles 14 can also spray the lubricant directly onto
the rolling stock 6 to influence the strip flatness and the strip
stress distribution over the width of the strip.
[0060] While specific embodiments of the invention have been shown
and described in detail to illustrate the inventive principles, it
will be understood that the invention may be embodied otherwise
without departing from such principles.
* * * * *